Over the past decade, research in the field of epigenetics has revealed that chemically modified bases are abundant components of the human genome and has forced us to abandon the notion we've had since high school genetics that DNA consists of only four bases.

Now, researchers at Weill Cornell Medical College have made a discovery that once again forces us to rewrite our textbooks. This time, however, the findings pertain to RNA, which like DNA carries information about our genes and how they are expressed. The researchers have identified a novel base modification in RNA which they say will revolutionize our understanding of gene expression.

Their report, published May 17 in the journal Cell, shows that messenger RNA (mRNA), long thought to be a simple blueprint for protein production, is often chemically modified by addition of a methyl group to one of its bases, adenine. Although mRNA was thought to contain only four nucleobases, their discovery shows that a fifth base, N6-methyladenosine (m6A), pervades the transcriptome.

Those who don't know history are destined to repeat it.

Edmund BurkeWe've known about modified bases in DNA since the early 1970s so there aren't any modern textbooks that don't mention them. If your high school genetics course didn't mention modified bases it isn't because scientists didn't know of their existence—unless, of course, you graduated from high school more than forty years ago.

We've known about the presence of N6-methyladenosine in mRNA for several decades. Here's the introduction to a 1984 paper by Horowitz et al. (1984).

The most prevalent internal methylated nucleoside in eukaryotic mRNA is N6-methyladenosine (m6A). This modified nucleoside is found in RNAs of higher eukaryotic organisms (1-6), plants (7-9), and viruses (3, 10-12), and occurs at two specific sequences: Gpm6ApC and Apm6ApC (13-17).

Refereences 1-5 are from 1975 meaning that in the published scientific literature the presence of m6A dates back 37 years. That's more than enough time to make it into the textbooks. It's in the textbooks.

Not only that, textbooks also contain references to two other modified bases in mRNA. N7-methylguanylate is common in cap structures and several mRNAs are known to contain inosine (I), a modified form of adenylate.

I blame the science writers at Cornell Medical Center for writing something that is not true and I blame the authors of the paper for hype and exaggeration and for not correcting the press release before it was published. That's not how science is supposed to work.

10 comments
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That one ranks among the worst press releases ever - when the paper itself refers to decades of prior work:

The distribution of m6A in RNA is poorly understood. Previousstudies have found that m6A exists in RNA from a variety of unique organisms, including viruses, yeast, and mammals (Beemon and Keith, 1977; Bodi et al., 2010). m6 A is found in tRNA (Saneyoshi et al., 1969), rRNA (Iwanami and Brown, 1968), and viral RNA (Beemon and Keith, 1977; Dimock and Stoltzfus, 1977). Although m6 A is detectable in mRNA-enriched RNA fractions (Desrosiers et al., 1974), it has been conﬁrmed in vivo inonly one mammalian mRNA (Horowitz et al., 1984).

I think that all university press releases should come with a statement that the authors and read the copy and approve its content.

Much of the time the researchers are sent a draft of the press release, will make copious changes, trying to rewrite most of it, and still wind up reading a generally poorly written piece of half digested science. Getting scientists to sign off on something means having them more involved in the writing process which is asking a lot, since they already wrote the paper, for little return, scientists don't read press releases.

Next, journal embargo restrictions are heavy-handed to start with and scare off a lot of university writers so they wind up either not writing anything until the day the embargo is lifted or not sending the researchers a draft until that day just to play it safe. There's also an unnecessary assumption that the person writing the press release is a science writer or knows any science. Most academics don't even bother to notify their university press office when they have a publication coming out, a testament to the likelihood that most think very little of their university press office. As such many press offices are woefully understaffed.

My university's policy is that only the press release office employees are allowed to write the release: not the scientists themselves and not even another qualified university staff employee, say a graduate student in another dept or lab. However, they are allowed to use press releases from the science journal or other science institutes and stamp their university name on it, which is hypocritical and unethical.

I think that all university press releases should come with a statement that the authors and read the copy and approve its content.

Much of the time the researchers are sent a draft of the press release, will make copious changes, trying to rewrite most of it, and still wind up reading a generally poorly written piece of half digested science. Getting scientists to sign off on something means having them more involved in the writing process which is asking a lot, since they already wrote the paper, for little return, scientists don't read press releases.

Next, journal embargo restrictions are heavy-handed to start with and scare off a lot of university writers so they wind up either not writing anything until the day the embargo is lifted or not sending the researchers a draft until that day just to play it safe. There's also an unnecessary assumption that the person writing the press release is a science writer or knows any science. Most academics don't even bother to notify their university press office when they have a publication coming out, a testament to the likelihood that most think very little of their university press office. As such many press offices are woefully understaffed.

My university's policy is that only the press release office employees are allowed to write the release: not the scientists themselves and not even another qualified university staff employee, say a graduate student in another dept or lab. However, they are allowed to use press releases from the science journal or other science institutes and stamp their university name on it, which is hypocritical and unethical.

Modified bases seem to be a pretty common topic in bad press releases; as evident in (http://sandwalk.blogspot.com/2009/04/modified-bases-in-dna.html). At least we aren't seeing press releases marvelling about the existence of selenocysteine or selenomethionine...

2011 Adenosine methylation in Arabidopsis mRNA is associated with the 3' end and reduced levels cause developmental defectshttp://www.frontiersin.org/Plant_Genetics_and_Genomics/10.3389/fpls.2012.00048/abstract

A few weeks ago, Larry posted this comment at Jonathan Eisen’s blog Tree of Life regarding scientific press releases:

All authors of the paper in question have to agree to the content of the press release and there should be a statement at the bottom of the press release naming each author and saying that they specifically approve the content.

I think the vast majority of scientists and science writers would agree with this solution on how to fix the increasing flow of deceiving press releases and misleading science communications. However, without a way of bringing this recommendation to their attention and that of the institutions writing these press releases and science communications, this flow will continue.

A potential solution would be for bloggers to join forces and promote this recommendation. Would that be possible?

Laurence A. Moran

Larry Moran is a Professor Emeritus in the Department of Biochemistry at the University of Toronto. You can contact him by looking up his email address on the University of Toronto website.

Sandwalk

The Sandwalk is the path behind the home of Charles Darwin where he used to walk every day, thinking about science. You can see the path in the woods in the upper left-hand corner of this image.

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Some readers of this blog may be under the impression that my personal opinions represent the official position of Canada, the Province of Ontario, the City of Toronto, the University of Toronto, the Faculty of Medicine, or the Department of Biochemistry. All of these institutions, plus every single one of my colleagues, students, friends, and relatives, want you to know that I do not speak for them. You should also know that they don't speak for me.

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Quotations

The old argument of design in nature, as given by Paley, which formerly seemed to me to be so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings and in the action of natural selection, than in the course which the wind blows.Charles Darwin (c1880)Although I am fully convinced of the truth of the views given in this volume, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. It is so easy to hide our ignorance under such expressions as "plan of creation," "unity of design," etc., and to think that we give an explanation when we only restate a fact. Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory.

Charles Darwin (1859)Science reveals where religion conceals. Where religion purports to explain, it actually resorts to tautology. To assert that "God did it" is no more than an admission of ignorance dressed deceitfully as an explanation...

Quotations

The world is not inhabited exclusively by fools, and when a subject arouses intense interest, as this one has, something other than semantics is usually at stake.
Stephen Jay Gould (1982)
I have championed contingency, and will continue to do so, because its large realm and legitimate claims have been so poorly attended by evolutionary scientists who cannot discern the beat of this different drummer while their brains and ears remain tuned to only the sounds of general theory.
Stephen Jay Gould (2002) p.1339
The essence of Darwinism lies in its claim that natural selection creates the fit. Variation is ubiquitous and random in direction. It supplies raw material only. Natural selection directs the course of evolutionary change.
Stephen Jay Gould (1977)
Rudyard Kipling asked how the leopard got its spots, the rhino its wrinkled skin. He called his answers "just-so stories." When evolutionists try to explain form and behavior, they also tell just-so stories—and the agent is natural selection. Virtuosity in invention replaces testability as the criterion for acceptance.
Stephen Jay Gould (1980)
Since 'change of gene frequencies in populations' is the 'official' definition of evolution, randomness has transgressed Darwin's border and asserted itself as an agent of evolutionary change.
Stephen Jay Gould (1983) p.335
The first commandment for all versions of NOMA might be summarized by stating: "Thou shalt not mix the magisteria by claiming that God directly ordains important events in the history of nature by special interference knowable only through revelation and not accessible to science." In common parlance, we refer to such special interference as "miracle"—operationally defined as a unique and temporary suspension of natural law to reorder the facts of nature by divine fiat.
Stephen Jay Gould (1999) p.84

Quotations

My own view is that conclusions about the evolution of human behavior should be based on research at least as rigorous as that used in studying nonhuman animals. And if you read the animal behavior journals, you'll see that this requirement sets the bar pretty high, so that many assertions about evolutionary psychology sink without a trace.

Jerry Coyne
Why Evolution Is TrueI once made the remark that two things disappeared in 1990: one was communism, the other was biochemistry and that only one of them should be allowed to come back.

Sydney Brenner
TIBS Dec. 2000
It is naïve to think that if a species' environment changes the species must adapt or else become extinct.... Just as a changed environment need not set in motion selection for new adaptations, new adaptations may evolve in an unchanging environment if new mutations arise that are superior to any pre-existing variations

Douglas Futuyma
One of the most frightening things in the Western world, and in this country in particular, is the number of people who believe in things that are scientifically false. If someone tells me that the earth is less than 10,000 years old, in my opinion he should see a psychiatrist.

Francis Crick
There will be no difficulty in computers being adapted to biology. There will be luddites. But they will be buried.

Sydney Brenner
An atheist before Darwin could have said, following Hume: 'I have no explanation for complex biological design. All I know is that God isn't a good explanation, so we must wait and hope that somebody comes up with a better one.' I can't help feeling that such a position, though logically sound, would have left one feeling pretty unsatisfied, and that although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist

Richard Dawkins
Another curious aspect of the theory of evolution is that everybody thinks he understand it. I mean philosophers, social scientists, and so on. While in fact very few people understand it, actually as it stands, even as it stood when Darwin expressed it, and even less as we now may be able to understand it in biology.

Jacques Monod
The false view of evolution as a process of global optimizing has been applied literally by engineers who, taken in by a mistaken metaphor, have attempted to find globally optimal solutions to design problems by writing programs that model evolution by natural selection.